- Email: [email protected]
Schwannoma with tentorial attachment in the cerebellopontine angle mimicking a meningioma
Case reports / Journal of Clinical Neuroscience 14 (2007) 797–801
797
Schwannoma with tentorial attachment in the cerebellopontine angle mimicking a meningioma K.H. Carlos Chung a
a,*
, Maya Cherian b, K. Nadana Chandran
a
Department of Neurosurgery, The Canberra Hospital, P.O. Box 11, Woden, 2606 ACT, Australia b Department of Anatomical Pathology, The Canberra Hospital, Canberra, ACT, Australia Received 14 February 2006; accepted 14 May 2006
Abstract Intracranial schwannoma not associated with the cranial nerves is rare. It is also an intriguing neoplasm since the Schwann cell is not native to the central nervous system. To date only four cases of intracranial schwannoma arising from the tentorium have been reported. We present a 49-year-old woman who harboured a schwannoma with a tentorial attachment in the right cerebellopontine angle and describe the relevant clinical, radiological and pathological findings. In addition, we briefly review the main hypotheses for the origin of this neoplasm and highlight its resemblance to meningioma and inclusion as a differential diagnosis. 2006 Elsevier Ltd. All rights reserved. Keywords: Schwannoma; Tentorium; Dura; Cerebellopontine angle; Meningioma
1. Case report
1.2. Operation
A 49-year-old woman with no stigmata of neurofibromatosis presented with a 2-week history of right hemicranial headache and neck pain, vomiting and unsteadiness of gait with drift to the right. Examination revealed a right facial paresis and paraesthesia, which was accompanied by slightly depressed corneal sensation and reflex.
A right retrosigmoid suboccipital craniotomy using frameless stereotaxy was performed. At operation the lesion was adherent to the tentorial and petrosal dura, but dissected away easily from the parenchyma and complete macroscopic resection was achieved. The cranial nerve complexes V, VII, VIII and IX–XI were all identified and preserved, and the mass was not found to be associated with these cranial nerves. Frozen section demonstrated a spindle cell tumour with some nuclear enlargement and hyperchromasia and a provisional diagnosis of meningioma was made. The patient made an uneventful recovery and was discharged on post-operative day 8. At 6-weeks follow-up, she was progressing well and except for residual paraesthesia involving the right mandible, she was symptom-free and neurologically intact.
1.1. Radiology A CT brain scan showed a contrast-enhancing meningeal-based 4 · 2.3 · 2.6-cm bi-lobed soft tissue mass, with central low density in the right cerebellopontine angle with local mass effect on the brainstem but no hydrocephalus. The internal auditory meatus was not widened, and there were no peri-tumoral oedema or adjacent bone hyperostosis. An MRI brain scan demonstrated a lobulated heterogeneous enhancing cystic lesion with meningeal enhancement along the inferior aspect of the tentorium and anteriorly along the sphenoid wall in the right cerebellopontine region indenting the brainstem (Fig. 1). The T2-weighted posterior fossa images showed no involvement of the right internal auditory meatus, nor the 7th or 8th cranial nerves (Fig. 2).
*
Corresponding author. Tel.: +612 6244 2222. E-mail address: [email protected] (K.H. Carlos Chung).
1.3. Pathology Light microscopy revealed a spindle cell tumour with a loosely textured pattern and foam cells and mast cells. There was also nuclear hyperchromasia and pleomorphorism seen, but no meningothelial whorls (Fig. 3). Immunohistochemistry for epithelial membrane antigen, cytokeratins AE1/AE3, CK8/18, and glial fibrillary acidic protein were negative, and positive for S100 (Fig. 4). Tissue was also processed for electron microscopy which demonstrated neoplastic spindle cells with long thin intertwining processes with basal lamina surrounded by collagen fibres consistent with Schwannian differentiation.
798
Case reports / Journal of Clinical Neuroscience 14 (2007) 797–801
Fig. 3. Light microscopy with haematoxylin and eosin stain showing a spindle cell tumour in a loosely textured pattern (·20 magnification).
Fig. 1. Coronal T1-weighted MRI of the brain with gadolinum demonstrating a lobulated heterogeneous enhancing cystic mass with meningeal enhancement along the inferior aspect of the tentorium.
Fig. 4. Immunohistochemistry stain with positive staining for S100 (·20 magnification).
Fig. 2. Axial T2-weighted MRI of the posterior fossa showing no involvement of the right internal auditory meatus.
2. Discussion Intracranial schwannomas account for about 6.8–8.0% of all primary brain tumours, of which 80–90% are found in relation to the vestibulocochlear nerve. Other cranial nerves such as the trigeminal, facial, and hypoglossal nerves may also be involved.1 Indeed, intracranial schwannoma unrelated to cranial nerves is unusual as the central nervous system is devoid of Schwann cells. In 1966 Gibson et al. published what appears to be the first recorded case of an intracerebral Schwann cell tumour in the temporal lobe of a 6 year-old boy.2 Since that time, fewer than 50 similar
cases have been reported. A thorough search of English language literature has revealed most cases arose as intra-axial lesions in the supratentorial compartment, and only 13 were attached to the dura (Table 1),3–15 of which four were in the posterior fossa attached to the tentorium (Table 2).10–13 In addition, we report an extracanalicular schwannoma with tentorial attachment occurring in the right cerebellopontine angle of a 49-year-old woman. The incidence of vestibular schwannoma increases with age and peaks between the fourth and sixth decades; there is also a female preponderance of 1.5–2.1.1 These are in contrast to the recent reviews of intracerebral schwannoma, which have attributed different clinical characteristics. Reports have suggested a relatively younger age at presentation and a male preponderance. Casadei et al. reported a mean age of 23.5 years with 79.3% of patients less than 29 years and a slight male preponderance of 1.6.16 Most lesions are benign and involve the supratentorial
Case reports / Journal of Clinical Neuroscience 14 (2007) 797–801
compartment. The common presenting symptoms are headaches and/or seizure. Sporadic cases involving the ventricular system, cerebellum, brainstem, spinal cord, pituitary fossa and dura, as well as malignant schwannoma have also been described.15,17–21 Due to the rarity and limited published literature of parenchymal schwannoma, its histogenesis remains speculative. Many theories have been proposed to explain the origin of these tumours. One theory, based on their occurrence in a younger cohort with one patient as young as 6 months,22 is that they represent a developmental neoplasm from disordered embryogenesis.23 This is supported by Feigin et al.’s observations that Schwann cells may be derived from differentiation of multipotential mesenchymal neural crest cells, and displaced neural crest cells as a result of failed migration in embryonic life. This may explain the occurrence of intracerebral schwannoma.24 There are other proposed sources for ectopic Schwann cells in the central nervous system. Schwannosis was a term coined by Russell and Rubinstein for hamartomatous lesions consisting of Schwann cells, which is thought to be related to the reticulin fibers in the pons and spinal cord.20,25 Non-neoplastic proliferation of Schwann cells of the perivascular nerve plexus, especially autonomic nerves, may be demonstrated in long-standing spinal diseases of diverse nature, and this has been postulated as the origin of intramedullary schwannoma.26,27 Furthermore, ectopic Schwann cells have also been described in certain pathological conditions, for example within multiple sclerosis plaques and at the edge of old infarcts.28 In order to help our understanding of this rare clinical entity, Haga et al. suggested a classification system based on location, that is, intra-axial schwannoma, periventricular schwannoma, schwannoma with dural attachment and others.29 Given their clinical heterogeneity, it is possible that different subsets may have different aetiologies. For
799
Table 2 Radiological features of schwannoma with tentorial attachment Authors, year
CT features
MRI features
Jabbour et al. 200210
No data available
Oikawa et al. 200211
No data available
Ozawa et al. 200312
Isodense partly cystic lesion No calcification No peri-tumoral oedema No adjacent bony hyperostosis Heterogeneously enhancing cystic lesion No calcification No peri-tumoral oedema No adjacent bony hyperostosis Central low density No calcification No peri-tumoral oedema No adjacent bony hyperostosis
Homogeneously enhancing mass Dural tail sign No peri-tumoral oedema Heterogeneously enhancing cystic lesion Dural tail sign No peri-tumoral oedema Heterogeneously enhancing cystic lesion Dural tail sign No peri-tumoral oedema
Du et al. 200313
Present Case
Heterogeneously enhancing cystic lesion No dural tail sign No peri-tumoral oedema
Heterogeneously enhancing cystic lesion Dural tail sign No peri-tumoral oedema
example, intra-axial schwannoma may be derived from schwannosis or multipotential mesenchymal cells of the neural crest, periventricular schwannomas from autonomic nerves of the choroid plexus, and there are several plausible explanations for schwannomas which have a dural attachment. They may arise from the trigeminal, vagal or upper cervical nerves which innervate the dura and tentorium, or they may be from the perivascular nerve fibers within the subarachnoid space. Another possibility was suggested by Russell and Rubinstein, who noted the histological resemblance of neuroectodermal Schwann cells and mesodermal pial cells.25 It is possible that dural-based
Table 1 Case reports of dural-based intracranial schwannoma Authors, year
Location of tumour
Age/sex
Presenting features
Hockley et al. 1975 Bruni et al. 19844 Vaquero et al. 19905 Ghosh et al. 19926 Huang et al. 19977 Horgan et al. 19988 Perunovic et al. 20029 Jabbour et al. 200210a Nakayama et al. 200215 Oikawa et al. 200211a Ozawa et al. 200312a Du et al. 200313a,b Takei et al. 200515
Right temporal Left frontal parasagittal Falx · 3 Right parasagittal Subfrontal Torcula Subfrontal Right tentorium cerebelli Left frontal Left tentorium cerebelli Right CPA Left suprasellar cistern and CPA Left frontoparietal
11/M 39/M 17/F 27/M 33/M 27/M 29/M 9/F 53/M 41/F 29/M 17/F 33/F
Present casea
Right CPA
49/F
Right proptosis, pupillary dilation, extraocular muscle palsy Seizure, neurofibromatosis Seizure, previous craniotomy Headache, seizure, hemiparesis Headache, decreased vision, lethargy, loss of consciousness Tender mass Headache, right abducens nerve palsy Headache, dizziness, nausea, vomiting, unsteady gait Seizure Headache, positional vertigo, truncal ataxia Headache, transient diplopia Headache, occasional diplopia Headache, paraesthesia and weakness of right upper extremity, right facial droop Headache, right facial paresis and paraesthesia
3
CPA = cerebello pontine angle. a Reported cases of schwannoma with tentorial attachment. b Schwannoma suspected to have arisen from the tentorium but may be a trochlear nerve schwannoma.
800
Case reports / Journal of Clinical Neuroscience 14 (2007) 797–801
schwannomas arise as a result of Schwann cell transformation from the pia. However, the origin of this dural-based cerebellopontine schwannoma remains enigmatic. The majority of schwannomas unrelated to cranial nerves are benign neoplasms with excellent prognosis. Although there have been seven case reports of malignant schwannoma, all of which were associated with unfavourable outcome,17,19,30–34 the prognosis of benign intracerebral schwannoma appears to be influenced by the age at presentation. In the review by Casadei et al. they noted that patients less than 24 years had an indolent course while those in the older age group had a more rapid evolution of symptoms.16 However, it should be noted that only nine patients were included in that retrospective study and the observations in the older cohort may simply reflect poorer general health and reduced neurological reserve. Although there are no pathognomonic radiological features, several characteristics on CT scan and MRI have been attributed to intracerebral schwannoma. These include calcification, cyst formation, peritumoral oedema or glosis, and a superifical or periventricular location.16,35,36 With review of the five cases of tentorium-based schwannoma, the typical radiological appearance was that of a heterogeneous enhancing cystic lesion with a dural tail sign and no peri-tumoral oedema (Table 2). It is interesting to note that the dural tail sign may be unreliable and may be observed in conditions other than meningioma, such as primary and secondary brain tumour, intracranial infections and aneurysms.37,38 Given that these features are also characteristic of a cystic meningioma, one should consider tentorial schwannoma as a differential diagnosis of a mixed cystic and solid mass with a dural tail in the cerebellopontine angle. A differentiating feature may be bony hyperostosis seen in association with meningioma which has not been described with intracranial schwannoma. The differentiation of schwannoma and meningioma may also represent a diagnostic challenge on histology. Both neoplasms may be composed of spindle cells and can be difficult to distinguish, especially on frozen sections. Similar difficulties were also encountered by Louw et al. where two tumours thought to be schwannomas were subsequently found to be meningiomas on immunohistochemical profiling.39 In conclusion, intracranial schwannoma unrelated to cranial nerves is rare and those with dural attachment, even rarer. We have reported a fifth case of intracranial schwannoma with tentorial attachment in a 49-year-old woman which mimicked a meningioma radiologically and intraoperatively. Although the distinction between benign neoplasms such as meningioma and schwannoma is unlikely to influence the indications for surgery, the clinician should consider schwannoma as a differential diagnosis in patients with intracranial extra-axial cystic lesion with dural attachment, especially in the younger patient. Many hypotheses for the origin of this curious neoplasm have been proposed but the histogenesis of intracranial
schwannoma not associated with cranial nerves remains unclear. It may be that all proposed theories are accurate and that different mechanisms may be responsible for different subsets of intracranial schwannoma. References 1. Graham DI, Lantos PL, editors. Greenfield’s Neuropathology. New York: Arnold; 2002. 2. Gibson AA, Hendrick EB, Conen PE. Case reports. Intracerebral schwannoma. Report of a case. J Neurosurg 1966;24:552–7. 3. Hockley AD, Hendrick EB. Unilateral proptosis and intracranial schwannoma. Surg Neurol 1975;4:509–12. 4. Bruni P, Esposito S, Greco R, et al. Solitary intracerebral schwannoma in von Recklinghausen’s disease. Surg Neurol 1984;22:360–4. 5. Vaquero J, Martinez R, Coca S, et al. Schwannomas of the falx. Surg Neurol 1990;34:160–3. 6. Ghosh S, Chandy MJ. Solitary ectopic intracerebral schwannoma. Br J Neurosurg 1992;6:163–6. 7. Huang PP, Zagzag D, Benjamin V. Intracranial schwannoma presenting as a subfrontal tumor: case report. Neurosurgery 1997;40: 194–7. 8. Horgan MA, Kernan JC, Delashaw JB, et al. Schwannoma of the forcula presenting as an occipital mass. Case illustration. Journal of Neurosurgery 1998;89. 9. Perunovic B, Pople IK, Athanasiou A, et al. Test and teach. A large tumour arising from the cribriform plate. Intracranial schwannoma unrelated to a major cranial nerve. Pathology 2002;34:74–7. 10. Jabbour P, Rizk T, Lahoud GA, et al. Schwannoma of the tentorium cerebelli in a child. Case report. Pediatr Neurosurg 2002;36:153–6. 11. Oikawa A, Takeda N, Aoki N, et al. Schwannoma arising from the tentorium at an unusual location: case report. Neurosurgery 2002;50:1352–5. 12. Ozawa N, Nakayama K, Ohata K, et al. Tentorial schwannoma: a case report. Br J Radiol 2003;76:421–4. 13. Du R, Dhoot J, McDermott MW, et al. Cystic schwannoma of the anterior tentorial hiatus. Case report and review of the literature. Pediatr Neurosurg 2003;38:167–73. 14. Takei H, Schmiege L, Buckleair L, et al. Intracerebral schwannoma clinically and radiologically mimicking meningioma. Pathol Int 2005;55:514–9. 15. Nakayama K, Nakayama T, Matsuoka Y, et al. Supratentorial convexity leptomeningeal schwannoma: case report. Neurosurgery 2002;51:1295–7. 16. Casadei GP, Komori T, Scheithauer BW, et al. Intracranial parenchymal schwannoma. A clinicopathological and neuroimaging study of nine cases. J Neurosurg 1993;79:217–22. 17. Jung JM, Shin HJ, Chi JG, et al. Malignant intraventricular schwannoma. Case report. J Neurosurg 1995;82:121–4. 18. Kodama Y, Terae S, Hida K, et al. Intramedullary schwannoma of the spinal cord: report of two cases. Neuroradiology 2001;43: 567–71. 19. Maiuri F, Colella G, D’Acunzi G, et al. Malignant intracerebellar schwannoma. J Neurooncol 2004;66:191–5. 20. Prakash B, Roy S, Tandon PN. Schwannoma of the brain stem: case report. J Neurosurg 1980;53:121–3. 21. Perone TP, Robinson B, Holmes SM. Intrasellar schwannoma: case report. Neurosurgery 1984;14:71–3. 22. Tsuiki H, Kuratsu J, Ishimaru Y, et al. Intracranial intraparenchymal schwannoma: report of three cases. Acta Neurochir (Wein) 1997;139: 756–60. 23. Frim DM, Ogilvy CS, Vonsattal JP, et al. Is intracerebral schwannoma a developmental tumor of children and young adults? Case report and review. Pediatr Neurosurg 1992;18:190–4. 24. Feigin I, Ogata J. Schwann cells and peripheral myelin within human central nervous tissues: the mesenchymal character of Schwann cells. J Neuropathol Exp Neurol 1971;30:603–12.
Case reports / Journal of Clinical Neuroscience 14 (2007) 801–805 25. Russell DS, Rubinstein LJ. Russell and Rubinstein’s Pathology of Tumours of Nervous System. Baltimore: Williams and Wilkins; 1989, pp.535–560. 26. Riggs HE, Clary WU. A case of intramedullary sheath cell tumor of the spinal cord. Consideration of vascular nerves as a source of origin. J Neuropathol Exp Neurol 1957;16:332–6. 27. Rout D, Pillai SM, Radhakrishnan VV. Cervical intramedullary schwannoma. Case report. J Neurosurg 1983;58:962–4. 28. Nelson E, Rennels M. Innervation of intracranial arteries. Brain 1970;93:475–90. 29. Haga Y, Shoji H, Oguro K, et al. Intracerebral schwannoma–case report. Neurol Med Chir (Tokyo) 1997;37:551–5. 30. Beauchesne P, Mosnier JF, Schmitt T, et al. Malignant nerve sheath tumor of the right cerebral peduncle: case report. Neurosurgery 2004;54:500–3. 31. Doi E, Ozaki F, Yabumoto M, et al. Multiple malignant intracerebral schwannomas in von Recklinghausen’s disease–report of a case. No Shinkei Geka 1983;11:93–8, Japanese.
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32. Singh RV, Suys S, Campbell DA, et al. Malignant schwannoma of the cerebellum: case report. Surg Neurol 1993;39:128–32. 33. Stefanko SZ, Vuzevski VD, Maas AI, et al. Intracerebral malignant schwannoma. Acta Neuropathol 1986;71:321–5. 34. Tanaka M, Shibui S, Nomura K, et al. Malignant intracerebral nerve sheath tumor with intratumoral calcification. Case report. J Neurosurg 2000;92:338–41. 35. Zagardo MT, Castellani RJ, Rees JH, et al. Radiologic and pathologic findings of intracerebral schwannoma. AJNR Am J Neuroradiol 1998;19:1290–3. 36. Ezura M, Ikeda H, Ogawa A, et al. Intracerebral schwannoma: case report. Neurosurgery 1992;30:97–100. 37. Guermazi A, Lafitte F, Miaux Y, et al. The dural tail sign–beyond meningioma. Clin Radiol 2005;60:171–88. 38. Wallace EW. The dural tail sign. Radiology 2004;233:56–7. 39. Louw D, Sutherland G, Halliday W, et al. Meningiomas mimicking cerebral schwannoma. J Neurosurg 1990;73:715–9.
doi:10.1016/j.jocn.2006.05.008
Lhermitte-Duclos disease associated with Cowden syndrome Tze-Ching Tan a
a,*
, Luen-Cheung Ho
b
Department of Neurosurgery, Queen Elizabeth Hospital, 30 Gascoigne Road, Kowloon, Hong Kong b Department of Anatomical Pathology, Queen Elizabeth Hospital, Hong Kong Received 28 December 2005; accepted 28 June 2006
Abstract Lhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum, is a rare cerebellar lesion, which can cause mass effects in the posterior fossa. It may occur sporadically, or in association with Cowden syndrome. Cowden syndrome or multiple hamartoma-neoplasia syndrome, is an uncommon autosomal dominant condition characterized by mucocutaneous lesions and systemic malignancies. We report two patients with Lhermitte-Duclos disease and associated Cowden syndrome. The clinical, radiological and histopathological features and management strategies of this rare disease complex are discussed. 2006 Elsevier Ltd. All rights reserved. Keywords: Cowden syndrome; Dysplastic cerebellar gangliocytoma; Hamartoma-neoplasia syndrome; Lhermitte-Duclos disease
1. Introduction Lhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum, is a rare cerebellar lesion with features of both hamartoma and benign neoplasm.1 It typically presents with headaches, gait disturbance and cranial nerve dysfunctions in adults. Magnetic resonance imaging reveals non-enhancing lesions of the cerebellar hemisphere with a gyriform ‘tiger-striped’ appearance.2–4 Surgical excision remains the mainstay of treatment. Over the past decade, the *
Corresponding author. Tel.: +852 29586029; fax: +852 23845594. E-mail address: [email protected] (T.-C. Tan).
association with Cowden syndrome has been recognized with increasing frequency. Cowden syndrome or multiple hamartoma-neoplasia syndrome, is an unusual autosomal dominant condition characterised by mucocutaneous lesions, including facial papules, gingival papillomas and acral keratoses. Men and women are equally afflicted and there are associated systemic malignancies of the breast, thyroid and genitourinary system.5 The most common extracutaneous site for hamartomas and neoplasms is the thyroid, with 60% of patients having goitres or adenomas.6 Lhermitte-Duclos disease associated with Cowden syndrome was first reported in 1981.7 Padberg postulated in 1991 that the disease
797
Schwannoma with tentorial attachment in the cerebellopontine angle mimicking a meningioma K.H. Carlos Chung a
a,*
, Maya Cherian b, K. Nadana Chandran
a
Department of Neurosurgery, The Canberra Hospital, P.O. Box 11, Woden, 2606 ACT, Australia b Department of Anatomical Pathology, The Canberra Hospital, Canberra, ACT, Australia Received 14 February 2006; accepted 14 May 2006
Abstract Intracranial schwannoma not associated with the cranial nerves is rare. It is also an intriguing neoplasm since the Schwann cell is not native to the central nervous system. To date only four cases of intracranial schwannoma arising from the tentorium have been reported. We present a 49-year-old woman who harboured a schwannoma with a tentorial attachment in the right cerebellopontine angle and describe the relevant clinical, radiological and pathological findings. In addition, we briefly review the main hypotheses for the origin of this neoplasm and highlight its resemblance to meningioma and inclusion as a differential diagnosis. 2006 Elsevier Ltd. All rights reserved. Keywords: Schwannoma; Tentorium; Dura; Cerebellopontine angle; Meningioma
1. Case report
1.2. Operation
A 49-year-old woman with no stigmata of neurofibromatosis presented with a 2-week history of right hemicranial headache and neck pain, vomiting and unsteadiness of gait with drift to the right. Examination revealed a right facial paresis and paraesthesia, which was accompanied by slightly depressed corneal sensation and reflex.
A right retrosigmoid suboccipital craniotomy using frameless stereotaxy was performed. At operation the lesion was adherent to the tentorial and petrosal dura, but dissected away easily from the parenchyma and complete macroscopic resection was achieved. The cranial nerve complexes V, VII, VIII and IX–XI were all identified and preserved, and the mass was not found to be associated with these cranial nerves. Frozen section demonstrated a spindle cell tumour with some nuclear enlargement and hyperchromasia and a provisional diagnosis of meningioma was made. The patient made an uneventful recovery and was discharged on post-operative day 8. At 6-weeks follow-up, she was progressing well and except for residual paraesthesia involving the right mandible, she was symptom-free and neurologically intact.
1.1. Radiology A CT brain scan showed a contrast-enhancing meningeal-based 4 · 2.3 · 2.6-cm bi-lobed soft tissue mass, with central low density in the right cerebellopontine angle with local mass effect on the brainstem but no hydrocephalus. The internal auditory meatus was not widened, and there were no peri-tumoral oedema or adjacent bone hyperostosis. An MRI brain scan demonstrated a lobulated heterogeneous enhancing cystic lesion with meningeal enhancement along the inferior aspect of the tentorium and anteriorly along the sphenoid wall in the right cerebellopontine region indenting the brainstem (Fig. 1). The T2-weighted posterior fossa images showed no involvement of the right internal auditory meatus, nor the 7th or 8th cranial nerves (Fig. 2).
*
Corresponding author. Tel.: +612 6244 2222. E-mail address: [email protected] (K.H. Carlos Chung).
1.3. Pathology Light microscopy revealed a spindle cell tumour with a loosely textured pattern and foam cells and mast cells. There was also nuclear hyperchromasia and pleomorphorism seen, but no meningothelial whorls (Fig. 3). Immunohistochemistry for epithelial membrane antigen, cytokeratins AE1/AE3, CK8/18, and glial fibrillary acidic protein were negative, and positive for S100 (Fig. 4). Tissue was also processed for electron microscopy which demonstrated neoplastic spindle cells with long thin intertwining processes with basal lamina surrounded by collagen fibres consistent with Schwannian differentiation.
798
Case reports / Journal of Clinical Neuroscience 14 (2007) 797–801
Fig. 3. Light microscopy with haematoxylin and eosin stain showing a spindle cell tumour in a loosely textured pattern (·20 magnification).
Fig. 1. Coronal T1-weighted MRI of the brain with gadolinum demonstrating a lobulated heterogeneous enhancing cystic mass with meningeal enhancement along the inferior aspect of the tentorium.
Fig. 4. Immunohistochemistry stain with positive staining for S100 (·20 magnification).
Fig. 2. Axial T2-weighted MRI of the posterior fossa showing no involvement of the right internal auditory meatus.
2. Discussion Intracranial schwannomas account for about 6.8–8.0% of all primary brain tumours, of which 80–90% are found in relation to the vestibulocochlear nerve. Other cranial nerves such as the trigeminal, facial, and hypoglossal nerves may also be involved.1 Indeed, intracranial schwannoma unrelated to cranial nerves is unusual as the central nervous system is devoid of Schwann cells. In 1966 Gibson et al. published what appears to be the first recorded case of an intracerebral Schwann cell tumour in the temporal lobe of a 6 year-old boy.2 Since that time, fewer than 50 similar
cases have been reported. A thorough search of English language literature has revealed most cases arose as intra-axial lesions in the supratentorial compartment, and only 13 were attached to the dura (Table 1),3–15 of which four were in the posterior fossa attached to the tentorium (Table 2).10–13 In addition, we report an extracanalicular schwannoma with tentorial attachment occurring in the right cerebellopontine angle of a 49-year-old woman. The incidence of vestibular schwannoma increases with age and peaks between the fourth and sixth decades; there is also a female preponderance of 1.5–2.1.1 These are in contrast to the recent reviews of intracerebral schwannoma, which have attributed different clinical characteristics. Reports have suggested a relatively younger age at presentation and a male preponderance. Casadei et al. reported a mean age of 23.5 years with 79.3% of patients less than 29 years and a slight male preponderance of 1.6.16 Most lesions are benign and involve the supratentorial
Case reports / Journal of Clinical Neuroscience 14 (2007) 797–801
compartment. The common presenting symptoms are headaches and/or seizure. Sporadic cases involving the ventricular system, cerebellum, brainstem, spinal cord, pituitary fossa and dura, as well as malignant schwannoma have also been described.15,17–21 Due to the rarity and limited published literature of parenchymal schwannoma, its histogenesis remains speculative. Many theories have been proposed to explain the origin of these tumours. One theory, based on their occurrence in a younger cohort with one patient as young as 6 months,22 is that they represent a developmental neoplasm from disordered embryogenesis.23 This is supported by Feigin et al.’s observations that Schwann cells may be derived from differentiation of multipotential mesenchymal neural crest cells, and displaced neural crest cells as a result of failed migration in embryonic life. This may explain the occurrence of intracerebral schwannoma.24 There are other proposed sources for ectopic Schwann cells in the central nervous system. Schwannosis was a term coined by Russell and Rubinstein for hamartomatous lesions consisting of Schwann cells, which is thought to be related to the reticulin fibers in the pons and spinal cord.20,25 Non-neoplastic proliferation of Schwann cells of the perivascular nerve plexus, especially autonomic nerves, may be demonstrated in long-standing spinal diseases of diverse nature, and this has been postulated as the origin of intramedullary schwannoma.26,27 Furthermore, ectopic Schwann cells have also been described in certain pathological conditions, for example within multiple sclerosis plaques and at the edge of old infarcts.28 In order to help our understanding of this rare clinical entity, Haga et al. suggested a classification system based on location, that is, intra-axial schwannoma, periventricular schwannoma, schwannoma with dural attachment and others.29 Given their clinical heterogeneity, it is possible that different subsets may have different aetiologies. For
799
Table 2 Radiological features of schwannoma with tentorial attachment Authors, year
CT features
MRI features
Jabbour et al. 200210
No data available
Oikawa et al. 200211
No data available
Ozawa et al. 200312
Isodense partly cystic lesion No calcification No peri-tumoral oedema No adjacent bony hyperostosis Heterogeneously enhancing cystic lesion No calcification No peri-tumoral oedema No adjacent bony hyperostosis Central low density No calcification No peri-tumoral oedema No adjacent bony hyperostosis
Homogeneously enhancing mass Dural tail sign No peri-tumoral oedema Heterogeneously enhancing cystic lesion Dural tail sign No peri-tumoral oedema Heterogeneously enhancing cystic lesion Dural tail sign No peri-tumoral oedema
Du et al. 200313
Present Case
Heterogeneously enhancing cystic lesion No dural tail sign No peri-tumoral oedema
Heterogeneously enhancing cystic lesion Dural tail sign No peri-tumoral oedema
example, intra-axial schwannoma may be derived from schwannosis or multipotential mesenchymal cells of the neural crest, periventricular schwannomas from autonomic nerves of the choroid plexus, and there are several plausible explanations for schwannomas which have a dural attachment. They may arise from the trigeminal, vagal or upper cervical nerves which innervate the dura and tentorium, or they may be from the perivascular nerve fibers within the subarachnoid space. Another possibility was suggested by Russell and Rubinstein, who noted the histological resemblance of neuroectodermal Schwann cells and mesodermal pial cells.25 It is possible that dural-based
Table 1 Case reports of dural-based intracranial schwannoma Authors, year
Location of tumour
Age/sex
Presenting features
Hockley et al. 1975 Bruni et al. 19844 Vaquero et al. 19905 Ghosh et al. 19926 Huang et al. 19977 Horgan et al. 19988 Perunovic et al. 20029 Jabbour et al. 200210a Nakayama et al. 200215 Oikawa et al. 200211a Ozawa et al. 200312a Du et al. 200313a,b Takei et al. 200515
Right temporal Left frontal parasagittal Falx · 3 Right parasagittal Subfrontal Torcula Subfrontal Right tentorium cerebelli Left frontal Left tentorium cerebelli Right CPA Left suprasellar cistern and CPA Left frontoparietal
11/M 39/M 17/F 27/M 33/M 27/M 29/M 9/F 53/M 41/F 29/M 17/F 33/F
Present casea
Right CPA
49/F
Right proptosis, pupillary dilation, extraocular muscle palsy Seizure, neurofibromatosis Seizure, previous craniotomy Headache, seizure, hemiparesis Headache, decreased vision, lethargy, loss of consciousness Tender mass Headache, right abducens nerve palsy Headache, dizziness, nausea, vomiting, unsteady gait Seizure Headache, positional vertigo, truncal ataxia Headache, transient diplopia Headache, occasional diplopia Headache, paraesthesia and weakness of right upper extremity, right facial droop Headache, right facial paresis and paraesthesia
3
CPA = cerebello pontine angle. a Reported cases of schwannoma with tentorial attachment. b Schwannoma suspected to have arisen from the tentorium but may be a trochlear nerve schwannoma.
800
Case reports / Journal of Clinical Neuroscience 14 (2007) 797–801
schwannomas arise as a result of Schwann cell transformation from the pia. However, the origin of this dural-based cerebellopontine schwannoma remains enigmatic. The majority of schwannomas unrelated to cranial nerves are benign neoplasms with excellent prognosis. Although there have been seven case reports of malignant schwannoma, all of which were associated with unfavourable outcome,17,19,30–34 the prognosis of benign intracerebral schwannoma appears to be influenced by the age at presentation. In the review by Casadei et al. they noted that patients less than 24 years had an indolent course while those in the older age group had a more rapid evolution of symptoms.16 However, it should be noted that only nine patients were included in that retrospective study and the observations in the older cohort may simply reflect poorer general health and reduced neurological reserve. Although there are no pathognomonic radiological features, several characteristics on CT scan and MRI have been attributed to intracerebral schwannoma. These include calcification, cyst formation, peritumoral oedema or glosis, and a superifical or periventricular location.16,35,36 With review of the five cases of tentorium-based schwannoma, the typical radiological appearance was that of a heterogeneous enhancing cystic lesion with a dural tail sign and no peri-tumoral oedema (Table 2). It is interesting to note that the dural tail sign may be unreliable and may be observed in conditions other than meningioma, such as primary and secondary brain tumour, intracranial infections and aneurysms.37,38 Given that these features are also characteristic of a cystic meningioma, one should consider tentorial schwannoma as a differential diagnosis of a mixed cystic and solid mass with a dural tail in the cerebellopontine angle. A differentiating feature may be bony hyperostosis seen in association with meningioma which has not been described with intracranial schwannoma. The differentiation of schwannoma and meningioma may also represent a diagnostic challenge on histology. Both neoplasms may be composed of spindle cells and can be difficult to distinguish, especially on frozen sections. Similar difficulties were also encountered by Louw et al. where two tumours thought to be schwannomas were subsequently found to be meningiomas on immunohistochemical profiling.39 In conclusion, intracranial schwannoma unrelated to cranial nerves is rare and those with dural attachment, even rarer. We have reported a fifth case of intracranial schwannoma with tentorial attachment in a 49-year-old woman which mimicked a meningioma radiologically and intraoperatively. Although the distinction between benign neoplasms such as meningioma and schwannoma is unlikely to influence the indications for surgery, the clinician should consider schwannoma as a differential diagnosis in patients with intracranial extra-axial cystic lesion with dural attachment, especially in the younger patient. Many hypotheses for the origin of this curious neoplasm have been proposed but the histogenesis of intracranial
schwannoma not associated with cranial nerves remains unclear. It may be that all proposed theories are accurate and that different mechanisms may be responsible for different subsets of intracranial schwannoma. References 1. Graham DI, Lantos PL, editors. Greenfield’s Neuropathology. New York: Arnold; 2002. 2. Gibson AA, Hendrick EB, Conen PE. Case reports. Intracerebral schwannoma. Report of a case. J Neurosurg 1966;24:552–7. 3. Hockley AD, Hendrick EB. Unilateral proptosis and intracranial schwannoma. Surg Neurol 1975;4:509–12. 4. Bruni P, Esposito S, Greco R, et al. Solitary intracerebral schwannoma in von Recklinghausen’s disease. Surg Neurol 1984;22:360–4. 5. Vaquero J, Martinez R, Coca S, et al. Schwannomas of the falx. Surg Neurol 1990;34:160–3. 6. Ghosh S, Chandy MJ. Solitary ectopic intracerebral schwannoma. Br J Neurosurg 1992;6:163–6. 7. Huang PP, Zagzag D, Benjamin V. Intracranial schwannoma presenting as a subfrontal tumor: case report. Neurosurgery 1997;40: 194–7. 8. Horgan MA, Kernan JC, Delashaw JB, et al. Schwannoma of the forcula presenting as an occipital mass. Case illustration. Journal of Neurosurgery 1998;89. 9. Perunovic B, Pople IK, Athanasiou A, et al. Test and teach. A large tumour arising from the cribriform plate. Intracranial schwannoma unrelated to a major cranial nerve. Pathology 2002;34:74–7. 10. Jabbour P, Rizk T, Lahoud GA, et al. Schwannoma of the tentorium cerebelli in a child. Case report. Pediatr Neurosurg 2002;36:153–6. 11. Oikawa A, Takeda N, Aoki N, et al. Schwannoma arising from the tentorium at an unusual location: case report. Neurosurgery 2002;50:1352–5. 12. Ozawa N, Nakayama K, Ohata K, et al. Tentorial schwannoma: a case report. Br J Radiol 2003;76:421–4. 13. Du R, Dhoot J, McDermott MW, et al. Cystic schwannoma of the anterior tentorial hiatus. Case report and review of the literature. Pediatr Neurosurg 2003;38:167–73. 14. Takei H, Schmiege L, Buckleair L, et al. Intracerebral schwannoma clinically and radiologically mimicking meningioma. Pathol Int 2005;55:514–9. 15. Nakayama K, Nakayama T, Matsuoka Y, et al. Supratentorial convexity leptomeningeal schwannoma: case report. Neurosurgery 2002;51:1295–7. 16. Casadei GP, Komori T, Scheithauer BW, et al. Intracranial parenchymal schwannoma. A clinicopathological and neuroimaging study of nine cases. J Neurosurg 1993;79:217–22. 17. Jung JM, Shin HJ, Chi JG, et al. Malignant intraventricular schwannoma. Case report. J Neurosurg 1995;82:121–4. 18. Kodama Y, Terae S, Hida K, et al. Intramedullary schwannoma of the spinal cord: report of two cases. Neuroradiology 2001;43: 567–71. 19. Maiuri F, Colella G, D’Acunzi G, et al. Malignant intracerebellar schwannoma. J Neurooncol 2004;66:191–5. 20. Prakash B, Roy S, Tandon PN. Schwannoma of the brain stem: case report. J Neurosurg 1980;53:121–3. 21. Perone TP, Robinson B, Holmes SM. Intrasellar schwannoma: case report. Neurosurgery 1984;14:71–3. 22. Tsuiki H, Kuratsu J, Ishimaru Y, et al. Intracranial intraparenchymal schwannoma: report of three cases. Acta Neurochir (Wein) 1997;139: 756–60. 23. Frim DM, Ogilvy CS, Vonsattal JP, et al. Is intracerebral schwannoma a developmental tumor of children and young adults? Case report and review. Pediatr Neurosurg 1992;18:190–4. 24. Feigin I, Ogata J. Schwann cells and peripheral myelin within human central nervous tissues: the mesenchymal character of Schwann cells. J Neuropathol Exp Neurol 1971;30:603–12.
Case reports / Journal of Clinical Neuroscience 14 (2007) 801–805 25. Russell DS, Rubinstein LJ. Russell and Rubinstein’s Pathology of Tumours of Nervous System. Baltimore: Williams and Wilkins; 1989, pp.535–560. 26. Riggs HE, Clary WU. A case of intramedullary sheath cell tumor of the spinal cord. Consideration of vascular nerves as a source of origin. J Neuropathol Exp Neurol 1957;16:332–6. 27. Rout D, Pillai SM, Radhakrishnan VV. Cervical intramedullary schwannoma. Case report. J Neurosurg 1983;58:962–4. 28. Nelson E, Rennels M. Innervation of intracranial arteries. Brain 1970;93:475–90. 29. Haga Y, Shoji H, Oguro K, et al. Intracerebral schwannoma–case report. Neurol Med Chir (Tokyo) 1997;37:551–5. 30. Beauchesne P, Mosnier JF, Schmitt T, et al. Malignant nerve sheath tumor of the right cerebral peduncle: case report. Neurosurgery 2004;54:500–3. 31. Doi E, Ozaki F, Yabumoto M, et al. Multiple malignant intracerebral schwannomas in von Recklinghausen’s disease–report of a case. No Shinkei Geka 1983;11:93–8, Japanese.
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32. Singh RV, Suys S, Campbell DA, et al. Malignant schwannoma of the cerebellum: case report. Surg Neurol 1993;39:128–32. 33. Stefanko SZ, Vuzevski VD, Maas AI, et al. Intracerebral malignant schwannoma. Acta Neuropathol 1986;71:321–5. 34. Tanaka M, Shibui S, Nomura K, et al. Malignant intracerebral nerve sheath tumor with intratumoral calcification. Case report. J Neurosurg 2000;92:338–41. 35. Zagardo MT, Castellani RJ, Rees JH, et al. Radiologic and pathologic findings of intracerebral schwannoma. AJNR Am J Neuroradiol 1998;19:1290–3. 36. Ezura M, Ikeda H, Ogawa A, et al. Intracerebral schwannoma: case report. Neurosurgery 1992;30:97–100. 37. Guermazi A, Lafitte F, Miaux Y, et al. The dural tail sign–beyond meningioma. Clin Radiol 2005;60:171–88. 38. Wallace EW. The dural tail sign. Radiology 2004;233:56–7. 39. Louw D, Sutherland G, Halliday W, et al. Meningiomas mimicking cerebral schwannoma. J Neurosurg 1990;73:715–9.
doi:10.1016/j.jocn.2006.05.008
Lhermitte-Duclos disease associated with Cowden syndrome Tze-Ching Tan a
a,*
, Luen-Cheung Ho
b
Department of Neurosurgery, Queen Elizabeth Hospital, 30 Gascoigne Road, Kowloon, Hong Kong b Department of Anatomical Pathology, Queen Elizabeth Hospital, Hong Kong Received 28 December 2005; accepted 28 June 2006
Abstract Lhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum, is a rare cerebellar lesion, which can cause mass effects in the posterior fossa. It may occur sporadically, or in association with Cowden syndrome. Cowden syndrome or multiple hamartoma-neoplasia syndrome, is an uncommon autosomal dominant condition characterized by mucocutaneous lesions and systemic malignancies. We report two patients with Lhermitte-Duclos disease and associated Cowden syndrome. The clinical, radiological and histopathological features and management strategies of this rare disease complex are discussed. 2006 Elsevier Ltd. All rights reserved. Keywords: Cowden syndrome; Dysplastic cerebellar gangliocytoma; Hamartoma-neoplasia syndrome; Lhermitte-Duclos disease
1. Introduction Lhermitte-Duclos disease or dysplastic gangliocytoma of the cerebellum, is a rare cerebellar lesion with features of both hamartoma and benign neoplasm.1 It typically presents with headaches, gait disturbance and cranial nerve dysfunctions in adults. Magnetic resonance imaging reveals non-enhancing lesions of the cerebellar hemisphere with a gyriform ‘tiger-striped’ appearance.2–4 Surgical excision remains the mainstay of treatment. Over the past decade, the *
Corresponding author. Tel.: +852 29586029; fax: +852 23845594. E-mail address: [email protected] (T.-C. Tan).
association with Cowden syndrome has been recognized with increasing frequency. Cowden syndrome or multiple hamartoma-neoplasia syndrome, is an unusual autosomal dominant condition characterised by mucocutaneous lesions, including facial papules, gingival papillomas and acral keratoses. Men and women are equally afflicted and there are associated systemic malignancies of the breast, thyroid and genitourinary system.5 The most common extracutaneous site for hamartomas and neoplasms is the thyroid, with 60% of patients having goitres or adenomas.6 Lhermitte-Duclos disease associated with Cowden syndrome was first reported in 1981.7 Padberg postulated in 1991 that the disease